3 Answers
3

There are a lot of things you can do. Generally, the first rule is change the strings. If the intonation is still out, then you will have to do a little more work.

At this point I would recommend taking the guitar to a specialist technician, particularly so if this is your first time setting up a guitar. Even though the guitar was cheap, you have a good chance of messing something up quite badly if you are a bit inexperienced with these sorts of things. Plus, the cost of the setup from the technician will probably bring the total amount spent on the guitar to what a decent low-end guitar would cost anyway.

During the setup, the technician is likely to:

Adjust the neck and bridge piece so that the action is lower

File the nut down to correct levels or replace it entirely

Check the bridge for damage/cracks that could cause bad intonation

Possibly replace the bridge piece entirely with a 'compensated' saddle.

Cheaper acoustic guitars are likely to have a 'straight' saddle, to keep production costs lower. 'Straight' saddles are not the best at providing good intonation on a guitar.

For details about what 'straight' and 'compensated' saddles are, I'll borrow what I wrote in answer to this question:

Saddles also come in two different variants: straight and compensated. 'Straight' saddles are straight lines with a rounded top surface that the strings lie over. Compensated ones have recessed and prominent sections (particularly where the top B and E strings are) which aid the intonation, which can be hard to manage on an acoustic guitar.

Thanks, I think what I'm looking for is how to make a better compensated saddle. As a side question, If one comes with the guitar, I've always wondered if there is a quick way to ensure that it's installed in the right direction
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AnonymousJan 23 '11 at 17:28

1

If a compensated saddle comes with the guitar, then the recessed and prominent sections should be on the G and B strings. If it is backwards then is will be on the A and D strings, which is not good at all. Cheers
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Ali MaxwellJan 23 '11 at 17:33

Also, you can buy them fairly cheaply, you don't need to fix up a standard one, and I think it would also be fairly difficult to. Link to one on ebay: cgi.ebay.co.uk/…
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Ali MaxwellJan 23 '11 at 17:38

Change the strings if they're old because they're stretched out and can't keep tune and intonation, sure, but also be aware that string gauge and intonation are tied. If you're sharp, go heavy. If you're flat, go lighter. There's adjustments you can do before you get to the "replace the bridge" point.